Freezing fog and temperatures of -6C are to grip Britain with the brutal cold snap sparking a public health warning.
The elderly and those with heart and lung problems have been advised to stay indoors and heat their homes to 18C to fight off infections.
Coming days will see the mercury plummet well below zero, while a freezing fog will leave day time temperatures feeling particularly cold.
Public Health England’s weather alert is in place from Sunday to Tuesday where cloud cover in central and southern areas will leave temperatures feeling particularly chilly
Sunday will feel slightly warmer in the day, particularly in the north of Scotland, however, daytime temperatures will fall with the increasd chance of cloud and fog.
Simon Partridge, a meteorologist at the Met Office, said: “A widespread frost is likely come first thing in the morning so many of us will be scraping ice of the cars if you’re out early enough.
“Sunday morning starts off dry and bright but very chilly….but throughout the day there’s lots of decent dry weather. Lots of sunshine.
“Into the afternoon some there will be some decent sunny spells for many parts, with just a little more in the way of cloud for the far north west.
“Temperatures will be just below average for this time of year.”
He added that overnight on Sunday temperatures will again drop with another frost on Monday morning.
The weather will be milder in the north of Scotland where temperatures will reach as high as 10C.
The Met Office has also warned that people’s ears could pop tomorrow when Britain experiences the highest atmospheric pressure in decades.
Contrasting temperatures across the US and a south moving jet stream has pushed a pocket of unusually high pressure towards the UK.
Meteorologist Alex Burkhill said: “We have high pressure which means stabled and settled, but how high is the remarkable bit.
“It’s likely we could get atmospheric pressure of around 150 hPa.
“We have only had figures that high around ten times in the last hundreds of so year.
“The highest was 1,053.6hPA. That was 31 January, 1902, in Aberdeen.
“The high point is probably going to be towards the south west this time.”
Public Health England issued a cold weather alert on Saturday as temperatures in some areas plunged to -6c.
Forecaster Mark Wilson said: “The South West of England could see -2C (28.4F) locally on Saturday (evening) while the West and East Midlands will experience temperatures as low as -3C (26.6F).
“For the rest of the UK temperatures will be around -5C (23F) to -6 (21.2F) in the evenings on Saturday and Sunday.”
Meanwhile 4 flood warnings – where immediate action is required – are still in place along with 85 lesser flood alerts across England and Wales.
Met Office 5-day forecast
Fog patches in the west could persist all day in a few places. Otherwise, mostly dry with sunny periods after a frosty start. The odd shower near coasts in the south-east, whilst cloudier and windier in the far north.
Frost and patchy fog in southern areas, whilst cloudier skies further north bringing some rain or drizzle to the far north and north-west, where it will also be windy.
Dry with sunny spells in the south after frost and fog lifts. Cloudier in north-western parts with some rain in the far north, where it will be windy, but milder.
Outlook for Tuesday to Thursday:
Low cloud and patchy rain and drizzle will often affect central and northwestern areas; it will be bright at times in the northeast, while frost and fog plagues the south.